DEPARTMENT: Transportation & Capital Improvements
DEPARTMENT HEAD: Mike Frisbie
COUNCIL DISTRICTS IMPACTED: Citywide
SUBJECT:
Briefing on the residential-grade/safe soil removed from the Convention Center expansion site.
SUMMARY:
A Briefing on the residential-grade/safe soil removed from the Convention Center expansion site.
BACKGROUND INFORMATION:
In late 2013 and early 2014, the City removed 150,000 cubic yards of soil from the Convention Center expansion site and placed it on a City-owned property off Highway 151 that is zoned for development as a business park. The soil was not structurally sound to handle the load of the new Convention Center building. Two different environmental engineering firms, Geo Strata and Raba Kistner Environmental, determined that the soil excavated from the Convention Center property does not exceed regulatory standards for residential or commercial development as established by the Texas Commission on Environmental Quality (TCEQ). The soil is safe enough to use for backyards, ball fields and gardens in any neighborhood community. The data in the two reports does not conflict on this critical point.
Where the environmental reports differ is in the narrative recommendations made by the consultants. Geo Strata recommended that the soil either be used in place at the Convention Center or taken to a landfill for disposal. This would have cost an estimated $6 million and resulted in approximately 150,000 cubic yards of residential-grade soil being unnecessarily wasted in a landfill.
City staff did not agree with this conclusion and utilized Raba Kistner to perform a more thorough Environmental Assessment. While the Geo Strata study was limited to 10 borings, 9 of which actually were drilled, from the soil to be excavated, the Raba Kistner assessment added another 32 borings for a total of 41 successful borings, from the soil to be excavated. It was a far more thorough and comprehensive assessment, and it too, indicated that the soils were appropriate for re-use instead of being taken to a landfill.
The City Manager has directed the City's Metro Health Department to oversee an independent review to test the soil at the new location. The City hired a third firm, Weston Solutions, to test the soil now in place at the commercial property and expect the study to be completed within four weeks. A representative of the nearby San Antonio Food Bank was a member of the panel that selected Weston Solutions.
Additionally, Metro Health commissioned the Southwest Research Institute to test vegetables and topsoil from the community garden at the Food Bank. The tests confirmed that there are no elevated levels of minerals in the topsoil and the vegetables are safe for consumption.
ISSUE:
A Briefing on the residential-grade/safe soil removed from the Convention Center expansion site
ALTERNATIVES:
This is a staff briefing intended for informational purposes and does not require alternatives.
FISCAL IMPACT:
This is a staff briefing intended for informational purposes.
RECOMMENDATION:
This is a staff briefing does not necessitate a staff recommendation.